Abstract
Weak memory models determine the behavior of concurrent programs. While they are often understood in terms of reorderings that the hardware or the compiler may perform, their formal definitions are typically given in a very different style—either axiomatic or operational. In this paper, we investigate to what extent weak behaviors of existing memory models can be fully explained in terms of reorderings and other program transformations. We prove that TSO is equivalent to a set of two local transformations over sequential consistency, but that non-multi-copy-atomic models (such as C11, Power and ARM) cannot be explained in terms of local transformations over sequential consistency. We then show that transformations over a basic non-multi-copy-atomic model account for the relaxed behaviors of (a large fragment of) Power, but that ARM’s relaxed behaviors cannot be explained in a similar way. Our positive results may be used to simplify correctness of compilation proofs from a high-level language to TSO or Power.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
Notes
- 1.
Different models may include some additional relations (e.g., a dependency relation between events is used for Power, see Sect. 5).
- 2.
Lahav et al. [13] treat fence instructions as syntactic sugar for atomic updates of a distinguished location. Here, we have fences as primitive instructions that induce fence events in the program executions.
References
Coq development for this paper and further supplementary material. http://plv.mpi-sws.org/trns/
Adve, S.V., Gharachorloo, K.: Shared memory consistency models: a tutorial. Computer 29(12), 66–76 (1996)
Alglave, J., Kroening, D., Nimal, V., Tautschnig, M.: Software verification for weak memory via program transformation. In: Felleisen, M., Gardner, P. (eds.) ESOP 2013. LNCS, vol. 7792, pp. 512–532. Springer, Heidelberg (2013). doi:10.1007/978-3-642-37036-6_28
Alglave, J., Maranget, L., Tautschnig, M.: Herding cats: modelling, simulation, testing, and data mining for weak memory. ACM Trans. Program. Lang. Syst. 36(2), 7:1–7:74 (2014)
Batty, M., Memarian, K., Nienhuis, K., Pichon-Pharabod, J., Sewell, P.: The problem of programming language concurrency semantics. In: Vitek, J. (ed.) ESOP 2015. LNCS, vol. 9032, pp. 283–307. Springer, Heidelberg (2015). doi:10.1007/978-3-662-46669-8_12
Batty, M., Memarian, K., Owens, S., Sarkar, S., Sewell, P.: Clarifying and compiling C/C++ concurrency: from C++11 to POWER. In: Proceedings of the 39th Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, POPL 2012, pp. 509–520. ACM, New York (2012)
Batty, M., Owens, S., Sarkar, S., Sewell, P., Weber, T.: Mathematizing C++ concurrency. In: Proceedings of the 38th Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages. POPL 2011, pp. 55–66. ACM, New York (2011)
Boehm, H.J., Demsky, B.: Outlawing ghosts: avoiding out-of-thin-air results. In: Proceedings of the Workshop on Memory Systems Performance and Correctness. MSPC 2014, pp. 7:1–7:6. ACM, New York (2014)
Burckhardt, S., Musuvathi, M., Singh, V.: Verifying local transformations on relaxed memory models. In: Gupta, R. (ed.) CC 2010. LNCS, vol. 6011, pp. 104–123. Springer, Heidelberg (2010). doi:10.1007/978-3-642-11970-5_7
Demange, D., Laporte, V., Zhao, L., Jagannathan, S., Pichardie, D., Vitek, J.: Plan B: a buffered memory model for Java. In: Proceedings of the 40th Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages. POPL 2013, pp. 329–342. ACM, New York (2013)
Doko, M., Vafeiadis, V.: A program logic for C11 memory fences. In: Jobstmann, B., Leino, K.R.M. (eds.) VMCAI 2016. LNCS, vol. 9583, pp. 413–430. Springer, Heidelberg (2016). doi:10.1007/978-3-662-49122-5_20
Flur, S., Gray, K.E., Pulte, C., Sarkar, S., Sezgin, A., Maranget, L., Deacon, W., Sewell, P.: Modelling the ARMv8 architecture, operationally: concurrency and ISA. In: Proceedings of the 43rd Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages. POPL 2016, pp. 608–621. ACM, New York (2016)
Lahav, O., Giannarakis, N., Vafeiadis, V.: Taming release-acquire consistency. In: Proceedings of the 43rd Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages. POPL 2016, pp. 649–662. ACM, New York (2016)
Lamport, L.: How to make a multiprocessor computer that correctly executes multiprocess programs. IEEE Trans. Comput. 28(9), 690–691 (1979)
Morisset, R., Pawan, P., Zappa Nardelli, F.: Compiler testing via a theory of sound optimisations in the C11/C++11 memory model. In: Proceedings of the 34th ACM SIGPLAN Conference on Programming Language Design and Implementation. PLDI 2013, pp. 187–196. ACM, New York (2013)
Owens, S., Sarkar, S., Sewell, P.: A better x86 memory model: x86-TSO. In: Berghofer, S., Nipkow, T., Urban, C., Wenzel, M. (eds.) TPHOLs 2009. LNCS, vol. 5674, pp. 391–407. Springer, Heidelberg (2009). doi:10.1007/978-3-642-03359-9_27
Shasha, D., Snir, M.: Efficient and correct execution of parallel programs that share memory. ACM Trans. Program. Lang. Syst. 10(2), 282–312 (1988)
Vafeiadis, V., Balabonski, T., Chakraborty, S., Morisset, R., Zappa Nardelli, F.: Common compiler optimisations are invalid in the C11 memory model and what we can do about it. In: Proceedings of the 42nd Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages. POPL 2015, pp. 209–220. ACM, New York (2015)
Ševčík, J.: Safe optimisations for shared-memory concurrent programs. In: Proceedings of the 32nd ACM SIGPLAN Conference on Programming Language Design and Implementation. PLDI 2011, pp. 306–316. ACM, New York (2011)
Acknowledgments
We would like to thank the FM’16 reviewers for their feedback. This research was supported by an ERC Consolidator Grant for the project “RustBelt”, funded under Horizon 2020 grant agreement no. 683289.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2016 Springer International Publishing AG
About this paper
Cite this paper
Lahav, O., Vafeiadis, V. (2016). Explaining Relaxed Memory Models with Program Transformations. In: Fitzgerald, J., Heitmeyer, C., Gnesi, S., Philippou, A. (eds) FM 2016: Formal Methods. FM 2016. Lecture Notes in Computer Science(), vol 9995. Springer, Cham. https://doi.org/10.1007/978-3-319-48989-6_29
Download citation
DOI: https://doi.org/10.1007/978-3-319-48989-6_29
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-48988-9
Online ISBN: 978-3-319-48989-6
eBook Packages: Computer ScienceComputer Science (R0)